From patchwork Fri Sep 7 22:34:26 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alison Schofield X-Patchwork-Id: 10592645 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4CECF14E2 for ; Fri, 7 Sep 2018 22:33:49 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 3CAE52B030 for ; Fri, 7 Sep 2018 22:33:49 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 30E782B12D; Fri, 7 Sep 2018 22:33:49 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id CF1102B030 for ; Fri, 7 Sep 2018 22:33:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726434AbeIHDQz (ORCPT ); Fri, 7 Sep 2018 23:16:55 -0400 Received: from mga06.intel.com ([134.134.136.31]:35244 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726431AbeIHDQz (ORCPT ); Fri, 7 Sep 2018 23:16:55 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Sep 2018 15:33:47 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,344,1531810800"; d="scan'208";a="261683969" Received: from alison-desk.jf.intel.com ([10.54.74.53]) by fmsmga006.fm.intel.com with ESMTP; 07 Sep 2018 15:33:44 -0700 Date: Fri, 7 Sep 2018 15:34:26 -0700 From: Alison Schofield To: dhowells@redhat.com, tglx@linutronix.de Cc: Kai Huang , Jun Nakajima , Kirill Shutemov , Dave Hansen , Jarkko Sakkinen , jmorris@namei.org, keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, linux-mm@kvack.org Subject: [RFC 02/12] mm: Generalize the mprotect implementation to support extensions Message-ID: <2dcbb08ed8804e02538a73ee05a4283c54180e36.1536356108.git.alison.schofield@intel.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP Today mprotect is implemented to support legacy mprotect behavior plus an extension for memory protection keys. Make it more generic so that it can support additional extensions in the future. This is done is preparation for adding a new system call for memory encyption keys. The intent is that the new encrypted mprotect will be another extension to legacy mprotect. Signed-off-by: Alison Schofield --- mm/mprotect.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/mm/mprotect.c b/mm/mprotect.c index 68dc476310c0..56e64ef7931e 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -35,6 +35,8 @@ #include "internal.h" +#define NO_PKEY -1 + static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, pgprot_t newprot, int dirty_accountable, int prot_numa) @@ -402,9 +404,9 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev, } /* - * pkey==-1 when doing a legacy mprotect() + * When pkey==NO_PKEY we get legacy mprotect behavior here. */ -static int do_mprotect_pkey(unsigned long start, size_t len, +static int do_mprotect_ext(unsigned long start, size_t len, unsigned long prot, int pkey) { unsigned long nstart, end, tmp, reqprot; @@ -528,7 +530,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len, SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, unsigned long, prot) { - return do_mprotect_pkey(start, len, prot, -1); + return do_mprotect_ext(start, len, prot, NO_PKEY); } #ifdef CONFIG_ARCH_HAS_PKEYS @@ -536,7 +538,7 @@ SYSCALL_DEFINE3(mprotect, unsigned long, start, size_t, len, SYSCALL_DEFINE4(pkey_mprotect, unsigned long, start, size_t, len, unsigned long, prot, int, pkey) { - return do_mprotect_pkey(start, len, prot, pkey); + return do_mprotect_ext(start, len, prot, pkey); } SYSCALL_DEFINE2(pkey_alloc, unsigned long, flags, unsigned long, init_val)